Ion emitting materials are useful in ion guns for bombarding materials. Ion emitting materials are also used in analytical instruments, and may be used for other applications such as ion implantation.
Currently, however, there are no solid state ion sources which emit heavy negative ions (anions). The solid state ion sources in current commercial use all emit positive ions (cations). There are gas-fed ion guns which can be used to produce primarily positive ions but can also be used to produce the oxygen negative ion. These gas-fed ion guns have the disadvantage of loading the vacuum system with gas that must be pumped from the system, preventing operation at high vacuum. The gas guns can be used to produce the oxygen negative ion, but this anion has the disadvantage of being very light in mass, i.e., 16, whereas heavier ions are much more efficient for sputtering secondary ions of organic molecules from surfaces.
The existing problem with prior art ion producing materials is the inherent limitations of the materials themselves. Namely, ion emissions have typically been too low to be commercially viable in ion guns. Furthermore, the life span of the materials is short because the intensity of the ion emissions decreases over time when heated at sufficiently high temperatures to produce ion emissions. As the intensity of the ion emissions decreases over time due to the applied heat, it is necessary to apply more heat to keep the intensity of emissions up. However, as more heat is applied, the life of the materials is shortened even more, and the intensity of emissions decreases even sooner. This process typically results in short-lived ion-producing materials.
Accordingly, a main objective of the present invention is to provide a high intensity, long lasting anion emitting capable composition of matter and method for producing heavy anion emissions.